public boolean commonEnd(int[] a, int[] b) {
  if(a.length >=1 && b.length >=1)
  {
    if(a[0] == b[0] || a[a.length -1] == b[b.length-1])
    {
      return true;
    }
    else return false;
  }
  else
  {
  return false;
  }
}